"Not a door key," he returned, "but the key to a mystery. Being a woman you are interested in mysteries that have a beautiful society girl as their heroine of course?"

"I really must disappoint you," she said rather coldly, "and I don't quite understand why you are not quick to take the many hints I have dropped. Can't you see I want to sit here alone and think? Your own room will be just as comfortably furnished. In a sense this is a sort of second home to me. Mrs. Langley and I are related and this room is an old and favorite haunt when I'm depressed. Is it asking very much that you leave me here alone?"

"Under ordinary conditions no," he said suavely.

"These are ordinary conditions," she persisted.

"I'm not sure," he retorted. "Tell me this if you dare. Why have you the combination to a safe written on a little piece of mauve paper and concealed in the book on your lap?"

She turned very pale and the look she gave him turned his suspicion into a desire to protect her. The woman of the world air dropped from her and she looked a frightened pathetic and extraordinarily lovely child.

"What shall I do?" she cried helplessly. "You are a detective?"

"Not yet," he said smiling, "although later I intend to be. But I'm not here even as a great amateur. Consider me merely a notoriously good shot suffering equally from neuralgia and curiosity. You have the combination of a safe concealed in this room and you want me to go to bed so that you may take out wads of bank notes and pay your bridge debts. Is that right so far?"

"You are absolutely wrong," she cried with spirit. "I need no money and have no debts. There are no jewels in the safe."

"Letters of course," he said easily.

She did not speak for a moment. He could see she was wondering what she dare tell him. She could not guess that he knew of the three packages of letters each tied with green ribbon. It was, he supposed, the old story of compromising letters. Innocent enough, but letters that would spell evil tidings to the jealous fiance. They might have been written to Colonel Langley. Men of that heroic stamp often appealed to sentimental school girls and the colonel was undeniably handsome in his cold superior way. His heart ached for her. She was suffering. What had seemed so easy was now become a task of the greatest difficulty.

"Yes," she said deliberately, "letters. Letters I must have."

"Do you suppose I can stand by and see my host robbed?"

"If you have any generosity about you you can in this instance. I only want to destroy one letter because if it should ever be discovered it will hurt the man I love most in the world."

Anthony Trent groaned. He had guessed aright. There was some man of her own cla.s.s and station who did not love her well enough to overlook some little silly affectionate note sent to the _beau sabreur_ Langley perhaps a half dozen years before. It was a rotten thing to keep such letters. He looked at the girl again and cursed his luck that she was already engaged. Then he sighed and remembered that even were she free it could never be his lot to marry unless he confessed all. And he knew that to a woman of the type he wanted to marry this confession would mean the end of confidence the beginning of despair.

"I shall not stop you," he said.

She looked at him eagerly.

"And you'll never tell?"

"Not if they put me through the third degree."

"But ... oughtn't you to tell?" she asked.

"Of course," he admitted, "but I won't. I can see you are wondering why.

I'll tell you. I've been in just such a position--and I did what you are going to do."

Without another word she went swiftly to the concealed safe and began to manipulate the lock. For five minutes she tried and then turned to him miserably.

"It won't open," she wailed.

"I'll have a shot at it," he said gaily, and went down on his knees by her side. He soon found out why it remained immovable. It was an old combination. She did not understand his moves as he went through the same procedure which had opened it before. She only saw that the doors swung back. She did not see him pry the iron sheathing back with the jimmy. It was miraculously easy.

Then he crossed the room to his chair and lighted another cigarette.

"Help yourself," he cried and picked up the book which had held the combination.

The girl's back was to him and he could not see what she was doing. He heard the scratch of a match being lighted and saw her stooping over the stone fireplace. She was burning her past. Then he heard her sigh with relief.

"I shall never forget what you have done for me," she said holding out her hand.

"It was little enough," he said earnestly.

"You don't know just how much it was," the girl returned, "or how grateful I shall always be to you. If I hadn't got that letter! I shouldn't have got it but for you. And to think that tomorrow we shall be introduced as one stranger to another. I'm rather glad I don't know your name or you mine. It will be rather fun won't it, being introduced and pretending we've never met before. If you are not very careful the d.u.c.h.ess will suspect we share some dreadful secret."

"The d.u.c.h.ess is rather that way inclined, isn't she?" he said.

He held the hand she offered him almost uncomfortably long a time. She would look for him tomorrow in vain. He supposed she would begin by asking if there were any other Americans there except Conington Warren.

After a time she would find he was not a guest of the Langleys. She would come at last to know what he was. And with this knowledge there would come contempt and a deliberate wiping his image from her mind.

Anthony Trent had no sentimental excuses to offer. He had chosen his own line of country.

He looked at her again. It would be the last time. Perhaps there was a dangerously magnetic quality about his glance for the girl dropped her eyes.

"Faustus," he said abruptly, "sold his soul for a future. I think I'd be willing to barter mine for a past."

"_Au revoir_," she said softly.

When she had closed the door he walked across the room to shut the safe.

What secrets of hers, he wondered, had been shut up there so long. He found himself in a new and strange frame of mind. Why should he be jealous of what she might have written in the letter that was now ashes?

She had probably thought hero-worship was love. She had a splendid face he told himself. High courage, loyalty and breeding were mirrored in it.

He wondered what sort of a man it was who had won her.

He looked at the neatly-tied bundle of letters. It seemed as though they had hardly been touched. Suddenly he turned to the compartment where the long letter had lain, the letter from which he had made so many extracts, the letter it was imperative Colonel Langley should believe to be intact.

It was gone. In the hearth there were still some burned pages. He could recognize the watermark.

Anthony Trent had amiably a.s.sisted an unknown girl to destroy a letter whose safety meant a great deal to him. If Colonel Langley were to discover the loss it would be easy enough to put the blame upon the bicycle-riding American who had pretended to be a friend of Private William Smith.

As he thought it over Anthony Trent saw that the girl in blue had not lied to him, had not sought to entrap him by gaining his sympathy as the "Countess" had succeeded in doing before another open safe in New York.

He had a.s.sumed one thing and she had meant another.

What was William Smith to this unknown beauty? Trent gritted his teeth.

He was going to find out. At all events he now knew the real name of the private soldier who had shared the dug-out with him. The next thing was to find out where he lived.

CHAPTER FOUR

_A LADY INTERRUPTS_

Anthony Trent told the obliging manager of the Maids' Head Hotel that he was interested mainly in the study of cathedral churches and since he had now studied the magnificent Norwich cathedral would push on to Ely.

He found England an exceedingly easy place to shake off pursuers despite its small size. There were always junctions where he could change from one line to another without incurring suspicion. He started for Ely but was soon lost among the summer crowds which thronged the university city of Cambridge. The convenient system of merely claiming one's baggage and ordering a porter to take it to car or taxi rendered the tracking of it by baggage checks almost impossible.